We make a bet 56.94 in US dollars for 'first team wins' in BetChance using odds 1.8.
We make a bet 43.06 in US dollars for 'second team wins or draw' (event 2X) in BetFair using odds 2.38 (line 'double chances' 1X-12-2X).
In fact we make LAY 2X bet using line LAY 1.69, bet size is 62.44. Betting Exchange reserrves 43.06 on your account. This is your real 'bet'.
Total size of all bets in US dollars is 100. Total bets size contains not the LAY bet, but reserved sum for the LAY bet, because reserved sum is actual bet size in case of LAY bets.
If first team wins, we get 56.94*1.8 = 102.49,
our net profit is 2.49.
If second team wins or draws, we get 43.06*2.38 = 102.48,
our net profit is 2.48.